Project Summary Over $50 billion is spent annually in the US treating chronic, non-healing wounds, many of which face life- threatening complications due to infections. Wound infections are difficult to treat due to the frequency of antibiotic resistance as well as the formation of biofilms, a community of bacteria covered by an extracellular polymeric substance. Biofilm-related infections can result in a substantial increase in bacterial tolerance and resistance to antibiotics compared to their planktonic phenotype. Given the issues of resistance, the complex nature of biofilms, and poor clinical outcomes associated with chronic wounds, it is urgent that alternative treatments be developed to address the bacterial protective mechanisms that maintain these difficult-to-treat infections. Arrevus is pioneering a novel approach to provide an effective treatment option for chronic wound infections through the development of Designer Proline-rich Antimicrobial peptide Chaperone protein inhibitors (DPCs). ARV-1501, Arrevus? lead DPC, kills bacteria in two distinct ways; i) by disrupting the bacterial lipid membrane and ii) by selectively inhibiting the chaperone protein DnaK. DnaK is a ubiquitously expressed and highly conserved prokaryotic heat shock protein critical for bacterial survival in stress conditions and is associated with bacterial biofilm formation. Preliminary studies show that ARV-1501: 1) has anti-infective capabilities both alone and in combination with other small molecule antibiotics; 2) can re-sensitize multidrug resistant (MDR) bacteria to antibiotics; 3) does not exhibit off-target binding to the human homolog (Hsp70); and 4) has reduced bacterial load and enhanced healing in several wound infection models. In this Phase I STTR, Arrevus will obtain proof-of-concept data to support the use of ARV-1501 as a therapeutic option for treating multidrug resistant wound infections. In Aim 1, we will evaluate the in vitro efficacy of ARV-1501 alone and in combination with clinically relevant antibiotics against MDR S. aureus and P. aeruginosa, two microbes commonly associated with wound infections. In Aim 1A, we will determine the antimicrobial efficacy, and in Aim 1B, we will determine the anti-biofilm activity. In Aim 2, we will assess the anti- biofilm and antimicrobial capabilities of ARV-1501 alone and in combination with a clinically-utilized antibiotic using the rabbit ear wound model, in collaboration with Robert Galiano, M.D. (Northwestern University). The rabbit ear model is clinically relevant and will allow us to determine the anti-biofilm properties of ARV-1501 alone (Aim 2A) and in combination with a synergistic antibiotic determined in Aim 1 (Aim 2B). Successful completion of the proposed studies will provide the necessary efficacy data to support further development of ARV-1501 as a therapeutic agent for treating wound infections in Phase II. Development of an ARV-1501/antibiotic treatment for chronic wound infections has the potential to provide an alternative strategy to address these hard-to-treat infections and enhance patient outcomes.